Figure in service as a hard worker (5)
I believe the answer is:
navvy
'a hard worker' is the definition.
'navvy' can be an answer for 'worker' (navvy is a kind of worker). I am unsure of the 'a hard' bit.
'figure in service' is the wordplay.
'figure' becomes 'v' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'service' becomes 'navy' (navy is a kind of service).
'v' going inside 'navy' is 'NAVVY'.
'as' is the link.
Can you help me to learn more?
(Other definitions for navvy that I've seen before include "Canal labourer" , "Labourer working on canals, roads, railways etc?" , "Labourer, originally digging the canals" , "Construction labourer" , "Canal constructor" .)